低强度脉冲超声促进大鼠正畸性牙根吸收的修复

LIPUS repaired root resorption during orthodontic tooth movement in rats

目的研究低强度脉冲超声（10w-intensity pulsed ultrasound，LIPUS）对大鼠正畸性牙根吸收的作用。方法158只Wistar大鼠建立正畸牙移动根吸收的动物模型，100g初始力值加载于大鼠右侧上颌两中切牙与第一磨牙之间14d，随机分为空白对照组、加力组、100MW／cm^2超声治疗组和150MW／cm^2超声治疗组。应用扫描电镜观察牙根表面吸收状态，同时测量牙根吸收指数。结果LIPUS超声组降低了牙根吸收指数，100MW／cm^2超声治疗组（2．08±0．51）％与150MW／cm^2超声治疗组（2．78±0．52）％差异无统计学意义。高倍扫描电镜下可见修复性牙骨质形成。结论LIPUS对大鼠正畸性牙根吸收有修复作用。

Objective To examine the effect of low-intensity pulsed ultrasound （LIPUS） on root resorption in rats model used for study of orthodontic tooth movement. Methods 158 Wistar rats were included in the sample as animal model to study root resorption during orthodontic tooth movement. 100g of initial force was applied between the upper incisors and the upper first molar for 14 days. The rats were randomly classified into control group, experimental group, 100 MW/cm^2 LIPUS group and 150 MW/cm^2 IdPUS group. Root resorption were assessed by scanning electron microscopy. Results The LIPUS showed significant effect in decreasing root resorption during orthodontic tooth movement. No significant difference was noted between 100 MW/cm^2 LIPUS group （2.08±0.51） % and 150 MW/cm^2 LIPUS group（2.28±0.52）%. Formation of reparative cementum can be found by scanning electron microscopy. Conclusions LIPUS might be useful for reparation of mechanical stress-induced root resorption during orthodontic tooth movement.